You will not be able to buy a new laptop or desktop that will run Windows XP. All hardware components require software for the operating system to communicate with it; they are called "drivers". Manufacturers have not created Windows XP compatible drivers in a very long time. Everything needs drivers... the USB port, the WiFi card, the RJ-45 port to plug in the internet cable. Without compatible drivers those things will not work. Additionally, current 7th and 8th generation Intel CPUs will only allow you to install Windows 10. This also applies to AMD's Ryzen CPUs. Microsoft basically paid them to ensure the most current CPUs are not "compatible" with anything less than Windows 10.
Some old games can still be played on in Windows 10, though it may take some coaxing, you need to do a bit research by doing a Google search say something like "Sims 2 Windows 10". I can tell you for a fact that the Sims 2 is not compatible with anything beyond Windows XP based a question about it several years ago. I think some something like Star Wars: Knights of the Old Republic can be played, but not "out of the box".
The oldest games I have played in Windows 8.1 include Fallout 1, Fallout 2, Diablo 2, and Morrowind. I did not have any problems running those games and I am pretty sure they will also run in Windows 10. The oldest game I have played in Windows 10 is Fallout 3. These games can basically be played with Intel integrated graphics in core i3 / i5 / i7 CPUs.
While integrated graphics performance has come a long way since many of the games you have listed have been released, I recommend at least buying a laptop with a modest graphics card in case you want to play more modern game with low or medium graphics (depends on the game). The $550 Acer Aspire 5 A515-51G-53V6 is the least expensive laptop that has a dedicated nVidia mx150 GPU. It is a "mainstream", but it this was 2016 instead of 2018 the mx150 would be considered as an entry level gaming GPU because it's performance is between the GTX 950m and GTX 960m. Translation... pretty decent performance.
https/www.amazon.com/Acer-A515-51G-53V6-i5-8250U-Enabled-Obsidian/dp/B07BRGR426/ref=sr_1_3?ie=UTF8&qid=1534899087&sr=8-3&keywords=acer+mx150
Check out www.GoG.com which was formerly known as Good Old Games; but they no longer only sell old games. They do tweak older games that they sell to be compatible with modern computers and operating systems. So if you have an old game that you simply can't run on a new laptop, then check out their site, they may have it.